Is this investment account an IRA or other retirement account marked as "Single Mutual Fund" (in Edit Account Details, General tab)?
If so, you can change the selection to "No". That will allow cash to be held in the account and cash - related transactions to be recorded. But you still may not be able to create a "linked cash account".
I now want to link it back, but the "Show Cash in Linked Account" is missing in QW2018.
I have been using Quicken for a REALLY long time - certainly back to DOS days. At one time it either required the cash in retirement accounts to be in a separate account, or I selected that option when offered (doesn't really matter at the moment). So I currently have an investment account where the cash is in a linked cash account. What I want to do is combine them and get rid of the separate cash account (my use of "link it back" was probably misleading). I've seen mention about unchecking the linked account option, but that is not available on this account in QW2018. So I'm trying to figure out how to put the cash back into the retirement account without having to manually enter every transaction.